Rubber compositions traditionally are made with aromatic oil, which enables the rubber compositions to be more easily processed. Additionally, when the rubber composition is used in a tread rubber, the aromatic oil provides the tread rubber with improved traction. However, some European countries have passed regulations to limit the amount of aromatic oils used in the rubber compositions. Substitutes for aromatic oil, such as synthetic ester oils and hydrogenated aromatic oils, do not provide the same beneficial properties imparted by aromatic oils.
Thus, what is needed in the art is a rubber composition that contains low amounts of aromatic oils or no aromatic oils while nonetheless enables the rubber composition to exhibit many of the beneficial properties provided by the aromatic oil. This invention answers that need.